There are many types of diagnostics devices that use optical sensing, such as fluorescence or absorption, to detect the presence or amount of analyte in a sample, e.g., blood, urine, or saliva sample. Fluorescence detection, in particular, has been adapted to many different types of enzyme, antigen, antibody, metabolite, nucleic acid and cell-type assays because of the high sensitivity and wide availability of fluorescent probes, and the different types of assay formats which are well-adapted to fluorescent probes.
As examples, gene chips or protein chips for detecting analyte binding to one or more array regions on a chip typically employ fluorescent markers to detect analyte binding to the chip. Antigen-analyte binding events are easily measured in a solid-phase or homogeneous assay format that employs fluorescent probes. Fluorescence detection based on proximity effects that rely of fluorescence quenching provides another major area of diagnostics and detection that take advantage of fluorescence properties.
One limitation of fluorescence-detection assay, however, has been the need for special fluorescence readers. Although such readers may not be expensive, they have prevented widespread adoption of fluorescence assays in home-testing and in small-clinic medical or veterinary settings, and in other medical or field diagnostic applications, e.g., in the testing of air or water for bioagents, that would benefit from small, easily portable and/or disposable assay equipment.
It would therefore be useful to provide a diagnostics fluorescence-detection apparatus or device that is designed for home or small-clinic use, and which can be easily adapted to a disposable test unit or disposable assay cartridge. It would be further desirable to provide such a device capable of handling multiple samples and/or sample arrays, such as nucleic acids arrays.